四川大学自控原理第一章作业

汪旭鸿 电子信息 2013141452116 周一下午 宁芊老师

1.1

(a) The manual steering system of an automobile

Reference

controller actuator process Signal

error

the controller output the actuator output the process desired output Current path angel deviation steering wheel angel vehicle wheel angel path

Sensor output

Desired path

(b). Drebbel ’s incubator desired

Reference

controller actuator process Signal error the controller output the actuator output the process desired output Setting of length deviation the pressure open and close temperature Riser length difference

Sensor

Sensor output Present Riser length(float position)

(c).The water level controlled by a float and valve

Reference

controller actuator process Signal error the controller output the actuator output the process desired output Desired Water level the pressure open and close height Water level deviation

Sensor

Sensor output Present Riser length(float position)

(d).Watt ’s steam engine with fly -ball governor

Reference

controller actuator process Signal error the controller output the actuator output the process desired output Desired speed deviation the force steam speed engine speed speed difference

Sensor

Sensor output Present speed(Ball angel)

1.7

(a) Pressure: Pressure sensor （半导体型压力传感器）

Piezoelectric impedance diffusion semiconductor pressure sensor is in the formation of the semiconductor wafer

surface deformation, through the external force (pressure) make the chip deformation and piezoelectric impedance

effect, so that the change of impedance is transformed into electrical signals.

(b) Temperature :DS18B20 temperature sensor

DS18B20 digital temperature sensor wiring is convenient, can be applied to a variety of occasions, after encapsulated into fastness touch, small volume, easy to use, packaging forms, suitable for all kinds of small space equipment digital temperature test control field .

Three pins: VCC GND and I/O.

It is convenient to connect with MCU.

Driver ’s mind steering wheel The riser Damper Fire intensity alcohol container Float ball valve Water filling

dynamics Float ball The balls valve engine

Fly balls

(c) Liquid level: photoelectric liquid level transducer （光电水位传感器）

Photoelectric liquid level sensor is by using the reflection of light on the surface of two different medium refraction principle and development of new type of point contact type liquid level measurement and control device. It has simple structure, high positioning

accuracy; There is no mechanical parts, do not need to debug; High sensitivity and corrosion resistance; Less consumption. Small volume,

and many other advantages and gradually recognized by the market.

(d) Flow of liquid along a pipe: Capacitive Drop Sensor （电容液滴传感器）

The Water Sensor module is part of the Grove system. It indicates whether the sensor is dry, damp or completely immersed in water by measuring conductivity. The sensor traces have a weak pull-up resistor of 1 M惟.

The resistor will pull the sensor trace value high until a drop of water shorts the sensor trace to the grounded trace.

Believe it or not this circuit will work with the digital I/O pins of your Arduino or you can use it with the analog pins

to detect the amount of water induced contact between the grounded and sensor traces.

(e) Rotational Position：gravity sensor（Triaxial Accelerometer）

Gravity sensor is working according to the principle of piezoelectric effect. Piezoelectric effect is the so-called "for there is no center of symmetry ionic crystals in crystal on the external force except in the crystal deformation will also

change the crystal polarization state of the electric field are established within the crystals, this happened due to

mechanical force make the medium polarization phenomenon called positive piezoelectric effect". Gravity sensor is to

use the internal crystal deformation due to the acceleration of this feature. As a result of this deformation can

produce voltage, as long as the applied voltage and calculated the relationship between the acceleration and

acceleration can be converted into voltage output.

(f) Linear Position Ultrasonic distance measuring module

The ultrasonic ranging module can process 16 input signals simultaneously.The module has four

interfaces, respectively VCC，Trig，Echo and GND.Trig pin is equivalent to the switch of the module, give a Trig

pin for at least 10 us high level pulse signal, the module can begin to work.At this moment, the module will

automatically from the two "big trumpet" sent eight 40 KHZ square wave, and then automatically detect

whether there is a signal to return.If there is one signal returns, then the module of the Echo port will

output a high level, the duration of the high level, is the time of ultrasonic wave from sent to receive!Do we

need to do is to open the ultrasonic module, which is then sent via ultrasonic Echo know from to time can

receive.

(g) Linear velocity: pulse coder

Encoder (encoder) is converting signals or data preparation, available in the form of communication, signal

transmission and storage of equipment.The encoder angular displacement or linear displacement is converted into

electrical signals, also known as the encoder.We are the most commonly used incremental encoder is converting

displacement into periodic signal, then convert the electrical signals into count pulse, with the size of the

displacement of the number of pulse said.

(h) rotational Speed: MPU6050 gyroscope

Any toothed wheel or gear on a rotating part may be used to trigger a magnetic field

change which can be used to trigger an electrical counting circuit by use of a Hall effect

sensor. The pulses can then be counted over a set time interval to produce angular

velocity(角速度): Tachometer(测速计).